2011AJ....142..106R

We present a multi-epoch time-resolved high-resolution optical spectroscopy study of the short-period (P_orb= 11.2 hr) eclipsing M0V+M5V RS CVn binary V405 Andromeda. By means of indirect imaging techniques, namely Doppler imaging, we study the surface activity features of the M0V component of the system. A modified version of a Doppler imaging code, which takes into account the tidal distortion of the surface of the star, is applied to the multi-epoch data set in order to provide indirect images of the stellar surface. The multi-epoch surface brightness distributions show a low intensity "belt" of spots at latitudes ±40° and a noticeable absence of high latitude features or polar spots on the primary star of V405 Andromeda. They also reveal slow evolution of the spot distribution over ∼4 yr. An entropy landscape procedure is used in order to find the set of binary parameters that lead to the smoothest surface brightness distributions. As a result, we find M₁= 0.51±0.03 M_☉, M₂= 0.21±0.01 M_☉, R₁= 0.71±0.01 R_☉, and an inclination i = 65°±1°. The resulting systemic velocity is distinct for different epochs, raising the possibility of the existence of a third body in the system.